the.com/stepfather

means The man married to one's parent (usually the mother) who is not one's biological father.

from From Old English steop-, a prefix tied to words for bereavement and loss — it appears in steopcild, a bereaved or orphaned child. So 'step-' originally marked a relationship born of grief: a stepfather was the man who stepped into the gap left by death, and only later by divorce or remarriage. The word literally carries the memory of a missing parent. It's a cousin to German Stief- (as in Stiefvater), both descending from the same Germanic root for the orphaned.